Device for cyclically operating a firearm trigger

ABSTRACT

A device for cyclically operating a trigger of a firearm includes biasing means for biasing a finger applied to a trigger away from the trigger, and a contact switch coupled to the biasing means and configured to be disposed between the finger and the trigger. In response to the contact switch detecting contact between the finger and the trigger, the biasing means actuates to cyclically bias the finger away from the trigger.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/877,878, filed Sep. 13, 2013, which is hereby incorporated byreference.

FIELD OF THE INVENTION

The present invention relates generally to firearms, and moreparticularly to accessories for assisting in firing firearms.

BACKGROUND OF THE INVENTION

For hundreds of years, mankind has been fascinated with the propulsionof objects with black powder and the technology for enabling it. Whetherlaunching a cannonball thousands of yards or firing a handgun, the actis an amazing and exhilarating experience. For the hobbyist, discharginga fully automatic weapon is invigorating and can be an incredibly funand enjoyable sporting experience.

Many people have never experienced firing a fully automatic weapon.Fully automatic weapons—weapons which fire multiple rounds in responseto a single trigger pull—are heavily regulated at both the state andfederal level. Due in part to such legislation, but also because of lowsupply and complexity of manufacture, fully automatic weapons can beincredibly expensive.

As a result of the high price, low supply, and heavy regulation of fullyautomatic weapons, most hobbyists own only semi-automatic weapons. Forpurposes of definition, semi-automatic weapons are distinguished fromfully automatic weapons in that semi-automatic weapons fire only asingle shot for each pull of the trigger. There is thus a one-to-onecorrespondence between the discharge of a round from the firearm anddepression of the trigger of the firearm in a semi-automatic weapon.Continuously depressing the trigger of a semi-automatic weapon does notresult in the weapon discharging more than one bullet.

Various attempts have been made to modify semi-automatic weapons to firein a fully automatic mode. However, these modifications usually involvedismantling the weapon and fundamentally altering the mechanisms thatcontrol firing. Not only are modifications such as these generallyillegal, but they are also highly dangerous.

Others have attempted to supplement semi-automatic weapons withmechanisms that allow them to fire rapidly. However, these changes oftenmake the weapon unstable, such that the owner cannot achieve precisionor accuracy while shooting, and in some cases, may render the weapondangerous, illegal, or both. An improved way of firing a semi-automaticweapon like a fully automatic weapon is needed.

SUMMARY OF THE INVENTION

According to one of a plurality of embodiments according to theprinciple of the invention, a device for cyclically operating a triggerof a firearm includes a glove having a finger stall and a pull mountedover the finger stall. A drive mechanism is coupled to the pull to movethe finger stall rapidly from a bent configuration toward a straightconfiguration, thereby moving the finger stall away from the triggervery rapidly. When an operator attempts to continuously depress thetrigger, the pull cyclically retracts his finger in the finger stallfrom the trigger, causing the firearm to be fired rapidly.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings:

FIG. 1 is an enlarged side elevation view of a portion of a firearm;

FIGS. 2A and 2B are top and bottom perspective views, respectively, of afirst embodiment of a cyclical trigger operation device for use with thefirearm of FIG. 1, the device being constructed and arranged accordingto the principle of the invention;

FIG. 2C is a top perspective view of a second embodiment of a cyclicaltrigger operation device for use with the firearm of FIG. 1, the devicebeing constructed and arranged according to the principle of theinvention;

FIG. 3A is a top perspective view of a third embodiment of a cyclicaltrigger operation device for use with the firearm of FIG. 1, the devicebeing constructed and arranged according to the principle of theinvention;

FIG. 3B is a top perspective view of a fourth embodiment of a cyclicaltrigger operation device for use with the firearm of FIG. 1, the devicebeing constructed and arranged according to the principle of theinvention;

FIG. 4A is a top perspective view of a fifth embodiment of a cyclicaltrigger operation device for use with the firearm of FIG. 1, the devicebeing constructed and arranged according to the principle of theinvention;

FIG. 4B is a top perspective view of a sixth embodiment of a cyclicaltrigger operation device for use with the firearm of FIG. 1, the devicebeing constructed and arranged according to the principle of theinvention; and

FIG. 5 is a side elevation view of a seventh embodiment of a cyclicaltrigger operation device constructed and arranged according to theprinciple of the invention, illustrated as it would appear installed onthe firearm of FIG. 1.

DETAILED DESCRIPTION

Reference now is made to the drawings, in which the same referencecharacters are used throughout the different figures to designate thesame elements. FIG. 1 illustrates a portion of a firearm 10representative of the family of rifles including rifles such as the M-4,M-16, AR-15, and AR-10. Indeed, the firearm 10 is exemplary of manysemi-automatic weapons, and reference in this description will be madeto the firearm 10 with the understanding that the description appliesequally to other semi-automatic weapons, and that reference to thefirearm 10 is not meant to limit the present invention to a particularembodiment for use with an AR-15 firearm 10. The firearm 10 includes anupper receiver 11, a lower receiver 12, and a stock 13 coupled to an endof the upper receiver 11. The firearm 10 shown in FIG. 1 can beselectively set in either a semi- or fully-automatic mode; for purposesof discussion here, it will be assumed that the firearm 10 is set in thesemi-automatic mode to always fire in a semi-automatic mode such thatone bullet is discharged from the firearm 10 in response to eachdepression of a trigger 20. The trigger 20 is located on the lowerreceiver 12 just in front of a pistol grip 21 and within a rigid triggerguard 22 extending forward from the grip 21 and encircling the trigger20.

The space between the trigger 20 and the grip 21 is herein referred toas a depression gap and is marked with the reference character 23, andthe space in front of the trigger 20 is herein referred to as a fingergap and is marked with the reference character 24. The trigger itselfhas a rear face 25 which borders the depression gap 23, and an opposedfront face 26 which borders the finger gap 24.

To fire the firearm 10, the trigger 20 must be depressed. The trigger 20must be moved backward from a ready position, shown in FIG. 1, towardthe grip 21 to a depressed position into the depression gap 23.Generally, the operator moves the trigger 20 by first extending hisindex finger proximate the trigger 20, then placing his index fingerover the trigger 20, and then curling or bending the index finger inwardor pulling back on the trigger 20 to depress the trigger 20. Depressingthe trigger 20 once causes the firearm 10 to fire one bullet. Before thefirearm 10 can be fired again, the trigger 20 must return from thedepressed position to the ready position in FIG. 1, so the operator willlet go of or release the trigger 20. Firearms typically have a spring orother mechanism which returns the trigger 20 to the ready position. Thetrigger 20 generally moves back to the ready position faster than theoperator can extend his finger, so that every time the operator moveshis finger away from or off of the trigger 20, the trigger 20 will resetto the ready position. One having ordinary skill in the art will readilyunderstand this conventional operation of a trigger.

The present invention is a device that allows the operator of thefirearm 10 to fire the weapon rapidly at speeds which emulate thefully-automatic fire of a fully-automatic weapon. The present inventionaccomplishes this by quickly returning the operator's finger to anextended position to allow the trigger 20 to return to the readyposition, so that the trigger 20 may again be depressed by the finger ofthe operator. The operator feels as if he is firing a fully automaticweapon because he feels that he is continuously holding down ordepressing the trigger down and firing multiple shots, while the deviceis actually quickly moving his finger off the trigger.

A First Embodiment

FIG. 2A and FIG. 2B illustrate an embodiment of the present invention,constructed and arranged according to the principle of the invention,referred to as a cyclical trigger operation device (hereinafter, “CTOD”)and marked with the reference character 30. The CTOD 30 is adapted to beused with the firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 30includes a glove body 31 for receiving a human hand, having a palmarside 32 and an opposed dorsal side 33, a proximal end 34 with an opening36, and an opposed distal end 35. The glove body 31 has an exteriorsurface 40 and an opposed interior surface 41 which bounds and definesan interior volume for receiving a hand which has been applied throughthe opening 36. A strap 42 is disposed on the exterior surface 40 andhas an end secured to the exterior surface 40 and an opposed end free ofthe exterior surface 40. The strap 42 carries a fastener for adjustablyfastening the strap 42 across the exterior surface at the opening 36, soas to selectively adjust the diameter of the opening 36 to fit looselyor snugly on a hand. The fastener is preferably a hook-and-loopfastener, with complemental fastening components on the strap 42 and onthe exterior surface 40. In other embodiments, the fastener is a seriesof buttons, snap-buttons, magnets, or other suitable fasteners forreleasably adjusting the dimension of the opening 36. In yet otherembodiments, instead of a glove body 31, the CTOD 30 is applied andsecured on the hand with several adjustable straps. A lower strap formsan annular band at the distal end of the base pad 50. An upper strapforms an annular band at the other end of the base pad 50. The lower andupper straps are constructed similarly and are adjustable to fitsecurely on the operator's hand. In some embodiments, the lower andupper straps are continuous elastic bands. In other embodiments thelower and upper straps each have first and second strap members withfree ends which are secured to each other with hook-and-loop engagementelements, buttons, snap-buttons, magnets, or other suitable fasteners.

The glove body 31 includes a thumb stall 44, an index finger stall 45,and three other finger stalls 46. Each of the stalls 44, 45, and 46 arefull-fingered sleeves extending from the glove body 31 to closed distalends proximate the distal end 35 of the CTOD 30. In other embodiments,the stalls 44, 45, and 46 may only partially cover the thumb andfingers. The thumb stall 44 is for receiving a thumb of a human hand,the index finger stall 45 is for receiving the index finger, or triggerfinger, on a human hand, and the three remaining finger stalls 46 arefor receiving the middle, ring, and pinky fingers on a human hand. Eachof the stalls 44, 45, and 46 fits snugly over the respective fingers sothat there is little play in material over the fingers. The glove body31 and the finger stalls 44, 45, and 46 are constructed from a materialor combination of materials having material characteristics ofdurability and flexibility, such as nylon, polypropylene, or othersimilar material. Additionally, the palmar side 32 of the CTOD 30 mayhave a textured surface or pattern for enhanced gripping of an objectsuch as the pistol grip 21 of the firearm 10.

The CTOD 30 includes a pull assembly having a base pad 50, a rigid spar51 extending from the base pad 50 along the index finger stall 45, and apull 52 pivoted to the spar 51 and further extending along the indexfinger stall 45. The pull 52 is a generally elongate beam member havinga wide proximal end 53 proximate to the base pad 52 and formed with ahole 54. Two struts 55 and 56 extend from the proximal end 53 forwardlyalong either side of the index finger stall 45 to a distal end 60 of thepull 52. A wide, flat, coplanar stop 57 extends between the struts 55and 56 proximate to the proximal end 53.

A cradle 61 is disposed at the distal end 60 of the pull 52 for holdingthe index finger stall 45 and preferably cradling a finger installed inthe index finger stall 45. The cradle 61 is a concave, bowl-shapedmember at the distal end extending between and supported by the struts55 and 56. Seen best in FIG. 2B, a hole 62 is formed through the cradle61 at a generally central and intermediate location in the cradle 61.When the CTOD 30 is worn by an operator, the cradle 61 is disposed nearthe pad of the operator's finger, and the hole 62 is disposed at a sitealong the operator's finger at which his finger contacts the trigger 20.The hole 62 thus allows the operator to feel the trigger 20 when wearingthe glove body 31 and through the pull 52.

The pull 52 is pivoted to the spar 51 at a distal end 63 of the spar 51to move along a path identified with double-arrowed arcuate line A inFIGS. 2A and 2B. The distal end 63 of the spar 51 carries an axle 64extending between the struts 55 and 56 of the pull 52. The struts 55 and56 are mounted for pivotal movement to the axle 64 at a generallyintermediate location with respect to the proximal and distal ends 53and 60 of the pull 52, and between the second and third knuckles (wherethe first knuckle is the knuckle closest to the tip of the finger andthe third knuckle is the knuckle closest to the palm). The pull 52pivots between (1) a first position, in which the pull 52 is transverseto the spar 51 and the base pad 50, and the index finger stall 45, asshown in broken line in FIGS. 2A and 2B, is curled, as would occur whenthe operator is depressing his finger against the trigger 20 in a curledposition of the finger, and (2) a second position, in which the pull 52is generally parallel to the spar 51 and the base pad 50, and the indexfinger stall 45, as shown in solid line in FIGS. 2A and 2B, isstraightened, as would occur when the operator's finger is moved off ofthe trigger 20 in an extended position of the finger. Movement past thesecond position is limited by the stop 57, which, when the pull 52 is inthe second position thereof, is in contact with the spar 51 and preventsfurther movement along line A. In the first position of the pull 52, thepull 52 is proximate to the trigger 20, and in the second position ofthe pull 52, the pull 52 is away from the trigger 20.

Still referring to FIGS. 2A and 2B, the spar 51 supports the pull 52 andthe movement of the pull 52 through and between the first and secondpositions of the pull 52. The spar 51 is integrally formed to the basepad 50 and extends parallel from the base pad 50 to the distal end 63 ofthe spar 51. The base pad 50 carries a drive mechanism 65 forcontrolling the movement of the pull 52 and the index finger stall 45.

The base pad 50, which may be flexible, is applied to the dorsal side 32of the CTOD 30. The base pad 50 is a mount for a pneumatic cylinder 70with a stroke that is generally aligned along the length of the spar 51.The base pad 50 also carries a gas supply 71 to supply a gas to thepneumatic cylinder 70. In FIG. 2A, the gas supply 71 is a cylindricalhousing. The gas supply 71 is preferably a replaceable gas cartridge,such as a CO2 cartridge. Such CO2 cartridges can be coupled to thepneumatic cylinder 70. An onboard programmable logic controller 72 ismounted on the base pad 52 and powered by a small battery 73. Theprogrammable logic controller 72 controls the application and removal ofgas to and from the pneumatic cylinder 70. A plurality of switches 74are also carried on the base pad 52 and coupled to the programmablelogic controller 72, so that the user may depress or select one of theplurality of switches to instruct the programmable logic controller tocontrol the drive mechanism 65 in a particular, pre-programmed way, asis discussed later. A cable 75 extends from the pneumatic cylinder 70 tothe hole 54 in the proximal end 53 of the pull 52, thereby operativelycoupling the drive mechanism 65 to the pull 52 to impart movement to thepull 52 in response to actuation of the drive mechanism 65.

The pneumatic cylinder 70 is aligned with the index finger stall 45, andthe cable 75 is coupled to a piston in the pneumatic cylinder 70. Thepiston in the pneumatic cylinder 70 intermittently and cyclicallyreciprocates between a forward position and a retracted position in thepneumatic cylinder 70. Actuation of the pneumatic cylinder 70 retractsthe cable 75. When the index finger stall 45 is bent, such as wouldoccur when a finger applied to the index finger stall 45 is curledaround the trigger 20, the cable 75 is extended and ready to beretracted so as to extend the index finger stall 45 and the index fingerapplied thereto. When the cable 75 is retracted, the cable 75 is drawnback, and the proximal end 53 of the pull 52 is drawn toward theproximal end 34 of the glove body 31 to move the pull 52 into the secondposition thereof. This causes the index finger stall 45 to extend towarda straightened configuration. When the pneumatic cylinder 70 retractsthe cable 75 quickly, the operator's index finger is moved quicklytoward the extended and straightened position thereof.

In operation, an operator places his hand into the CTOD 30 by applyinghis hands fingers-first through the opening 36 and directing each of hisfingers into the appropriate finger stall. The operator ensures that thecradle 61 is on the underside of his finger. When the operator hascomfortably fit the CTOD 30 on his hand, he adjusts the strap 42 bydrawing the free end back away from the exterior surface 40 of the glovebody 31 and re-applying it so as to secure the fastener and fix thedimension of the opening 36 as is comfortably snug on the operator'swrist.

The operator then selects the desired performance of the CTOD 30 byselecting one of the plurality of switches 74. The switches 74 eachcorrespond to various performance functions of the CTOD 30. Some of theswitches allow the operator to select a cycling speed. For instance, theoperator may select a switch setting the cycling speed at three hundredrevolutions per minute (“rpm”), in response to which the pneumaticcylinder will reciprocate approximately three hundred times in oneminute to cycle movement of the pull 52 three hundred times in a minute,emanating a fast firing firearm. In another example, the operator mayselect a switch setting the cycling speed at nine hundred rpm, inresponse to which the pneumatic cylinder will reciprocate approximatelynine hundred times in one minute to cycle movement of the pull 52 ninehundred times in a minute, emulating a very fast firing firearm. Some ofthe switches allow the operator to select a cycling duration. Forexample, the operator may select a switch setting the cycling durationto three pulses, in which case the pneumatic cylinder will reciprocatethree times and then pause or stop, so as to emulate a three-round burstof fire. In another example, the operator may select a switch settingthe cycling duration to five pulses, in which case the pneumaticcylinder will reciprocate five times, so as to emulate a five-roundburst of fire. In yet another example, the operator may select a switchsetting the cycling duration to two seconds, in which case the pneumaticcylinder will reciprocate for two seconds, so as fire repeatedly for twoseconds and then pause or stop.

After setting the performance of the CTOD 30, the operator grips thefirearm 10 at the pistol grip 21, placing his index finger proximate tothe trigger 20. The operator shoulders or readies the firearm 10 andtakes aim at a target. Once a target is acquired, the operator fires theweapon by placing his finger against the trigger 20 and depressing orpulling the trigger 20 back toward the grip 21. Preferably, the operatorcontinuously depresses his finger against the trigger 20.

The cradle of the pull 52 carries a contact switch 80. As seen in FIG.2B, the contact switch 80 is located on the palmar side 32, orunderside, of the index finger stall 45, against the cradle 61 butwithin the hole 62, such that the contact switch 80 is disposed betweenthe finger applied to the index finger stall 45 and the trigger 20. Thecontact switch 80 is preferably a pressure switch which detects contactbetween the finger and the trigger 20, responsive to two to three poundssuch that when two to three pounds of pressure are applied at thecontact switch 80, the contact switch 80 issues an activation signal.When the operator's finger is placed against the trigger 20 and curledinto the first position of the pull 52, thus depressing to pull thetrigger 20, the contact switch 80 is closed, and the contact switch 80transmits an activation signal to the programmable logic controller 72in the drive mechanism 65.

The activation signal is transmitted along an electrical wire (notshown) which is coupled to the programmable logic controller 72, andwhich is preferably sewn into the index finger stall 45 and the glovebody 31. In response to receiving the signal, the programmable logiccontroller 72 causes gas to be intermittently and cyclically supplied toand drawn from the pneumatic cylinder 70, such as through an on-boardvalve, according to the pre-programmed control instructionscorresponding to the selected one the of the plurality of switches 74,causing the pneumatic cylinder 70 to reciprocate, and causing the cable75 to be intermittently and cyclically retracted. In response, theoperator's index finger, applied in the index finger stall 45 isintermittently and cyclically retracted toward the extended positionalong double-arrowed arcuate line A in FIGS. 2A and 2B. The operator,however, continues to hold his finger down in the curled position todepress the trigger 20. When the pneumatic cylinder 70 retracts thecable 75, a greater force is applied to the operator's finger than heapplies to it, so that the finger is pulled to the extended position andthe first position of the pull 52. In the extended position of thefinger, the finger is pulled off of or away from the trigger 20, and thetrigger 20 is returned to the ready position by the spring or othermechanism which returns the trigger 20 to the ready position. When thepneumatic cylinder 70 has retracted a full stroke, the supply of gas tothe pneumatic cylinder 70 is removed, as instructed by the programmablelogic controller 72, the operator's own force of his finger is now ableto overcome the pneumatic cylinder 70, and his finger curls along line Ato depress the trigger 20. When his finger depresses the trigger 20, itextends the pneumatic cylinder 70 a full stroke length so that thepneumatic cylinder 70 is ready to retract. With the operator continuingto curl his finger, and with the pneumatic cylinder 70 intermittentlyand cyclically retracting the cable 75 to intermittently and cyclicallyextend the finger, the pull 52 is intermittently and cyclically movedbetween the first and second positions thereof, the index finger stall45 is moved intermittently and cyclically between the bent andstraightened configurations, the operator's finger is intermittently andcyclically curled and extended, and the trigger 20 is intermittently andcyclically depressed to the depressed position and allowed to return tothe ready position. In this way, the firearm 10 intermittently andrapidly fires bullets, emulating fully-automatic fire.

A Second Embodiment

FIG. 2C illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 90. The CTOD 90 is adapted to be used withthe firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 90 is verysimilar to the CTOD 30 and includes many identical structural featureselements with the CTOD 30. Those structural features and elements of theCTOD 90 which are identical to corresponding structural features andelements in the CTOD 30 are marked with identical reference characters,but are designated with a prime (“′”) symbol to distinguish them fromthose of the CTOD 30. In some cases, the CTOD 90 has identicalstructural features and elements as the CTOD 30 but located in alternatelocations. In such cases, the same reference character will be used,with the prime symbol, but the alternate location will be described.Where the CTOD 90 has identical structural features and elements as theCTOD 30 and those structural features and elements are located and usedin an identical manner as in the CTOD 30, they will merely be listed, asdescribing them would be unduly repetitive and burdensome for thereader. It should be understood, then, that the description for theparticular structural feature or element with respect to the CTOD 30 isequally applicable to the corresponding identical structural feature andelement with respect to the CTOD 90, unless otherwise described.Finally, for simplicity of the illustrations, not all identicalreference characters will be shown, if their corresponding identicalreference characters are shown in a figure illustrating an alternateembodiment.

The CTOD 90 includes a glove body 31′, a dorsal side 32′, a palmar side33′, a proximal end 34′, a distal end 35′, an opening 36′, an exteriorsurface 40′, an interior surface 41′, a strap 42′, a thumb stall 44′, anindex finger stall 45′, and finger stalls 46′. The CTOD 90 includes abase pad 50′, a spar 51′ extending from a distal end 63′ at the base pad50′ to an axle 64′, and a pull 52′ pivoted to the axle 64′ on the spar51′ for movement along the double-arrowed arcuate line A′ in FIG. 2C.The pull 52′ includes a proximal end 53′, a hole 54′, struts 55′ and56′, a stop 57′, a distal end 60′, a cradle 61′, a hole 62′, and acontact switch 80′. The base pad 50′ also carries a pneumatic cylinder70′, which is coupled to the pull 52′ with a cable 75′. However, the gassupply 71′, the programmable logic controller 72′, the battery 73′, andthe switches 74′ are off of the glove body 31′, preferably on a mount orplatform 91 carried on a belt 92 around the operator's waist. A longhose 93 extends from the gas supply 71′, off the belt, across theoperator's torso, down the operator's arm, and onto the base pad 50′,where the hose 93 couples with the pneumatic cylinder 70′ to provide gasto the pneumatic cylinder 70′. With the gas supply 71′ located off theglove body 31′, a larger-sized gas supply 71′ is carried than in theCTOD 30, so that the gas supply 71′ lasts longer and needs to bereplaced less frequently than with the CTOD 30.

Operation of the CTOD 90 is similar to that of the CTOD 30. The pistonin the pneumatic cylinder 70′ intermittently and cyclically reciprocatesbetween a forward position and a retracted position in the pneumaticcylinder 70′. Gas is supplied to the pneumatic cylinder 70′ through thehose 93. Actuation of the pneumatic cylinder 70′ retracts the cable 75′.When the index finger stall 45′ is bent, such as would occur when afinger applied to the index finger stall 45′ is curled around thetrigger 20, the cable 75′ is extended and ready to be retracted so as toextend the index finger stall 45′ and the index finger applied thereto.When the cable 75′ is retracted, the cable 75′ is drawn back, and theproximal end 53′ of the pull 52′ is drawn toward the proximal end 34′ ofthe glove body 31′ to move the pull 52′ into the second positionthereof. This causes the index finger stall 45′ to straighten. When thepneumatic cylinder 70′ retracts the cable 75′ quickly, the operator'sindex finger is quickly returned toward the extended position thereof.

A Third Embodiment

FIG. 3A illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 100. The CTOD 100 is adapted to be usedwith the firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 100 isvery similar to the CTOD 30 and includes many identical structuralfeatures elements with the CTOD 30. Those structural features andelements of the CTOD 100 which are identical to corresponding structuralfeatures and elements in the CTOD 30 are marked with identical referencecharacters, but are designated with an asterisk (“*”) symbol todistinguish them from those of the CTOD 30. Where the CTOD 100 hasidentical structural features and elements as the CTOD 30, they willmerely be listed, as describing them would be unduly repetitive andburdensome for the reader. It should be understood, then, that thedescription for the particular structural feature or element withrespect to the CTOD 30 is equally applicable to the correspondingidentical structural feature and element with respect to the CTOD 100,unless otherwise described. Finally, for simplicity of theillustrations, not all identical reference characters will be shown, iftheir corresponding identical reference characters are shown in a figureillustrating an alternate embodiment.

The CTOD 100 includes a glove body 31*, a dorsal side 32*, a palmar side33*, a proximal end 34*, a distal end 35*, an opening 36*, an exteriorsurface 40*, an interior surface 41*, a strap 42*, a thumb stall 44*, anindex finger stall 45*, and finger stalls 46*. The CTOD 100 includes abase pad 50*, a spar 51* extending from a distal end 63* at the base pad50* to an axle 64*, and a pull 52* pivoted to the axle 64* on the spar51* for movement along the double-arrowed arcuate line A* in FIG. 2C.The pull 52* includes a proximal end 53*, a hole 54*, struts 55* and56*, a stop 57*, a distal end 60*, a cradle 61*, a hole 62*, and acontact switch 80*.

The base pad 50* carries a drive mechanism 101 for controlling themovement of the pull 52* and the index finger stall 45*. The base pad50* carries an electronic solenoid 102, which is coupled to the pull 52*with a cable 75*. The solenoid 102 includes a piston or piston head thatreciprocates through a stroke that is generally aligned parallel to thelength of the spar 51*. A battery 102 is coupled to the solenoid 102 toprovide the solenoid with power. An onboard programmable logiccontroller 72* is mounted on the base pad 52* and powered by the battery103. The programmable logic controller 72* controls the provision ofcurrent to the solenoid 102. A plurality of switches 74* are alsocarried on the base pad 52* and coupled to the programmable logiccontroller 72*, so that the user may depress or select one of theplurality of switches to instruct the programmable logic controller tocontrol the drive mechanism 101 in a particular, pre-programmed way.

The solenoid 102 is aligned with the index finger stall 45*, and thecable 75* is coupled to the piston in the solenoid 102. The piston inthe solenoid 102 intermittently and cyclically reciprocates between aforward position and a retracted position in the solenoid 102. Actuationof the solenoid 102 retracts the cable 75*. When the index finger stall45* is bent, such as would occur when a finger applied to the indexfinger stall 45* is curled around the trigger 20, the cable 75* isextended and ready to be retracted so as to extend the index fingerstall 45* and the index finger applied thereto. When the cable 75* isretracted, the cable 75* is drawn back, and the proximal end 53* of thepull 52* is drawn toward the proximal end 34* of the glove body 31* tomove the pull 52* into the second position thereof. This causes theindex finger stall 45* to straighten. When the solenoid 102 retracts thecable 75* quickly, the operator's index finger is quickly returnedtoward the extended position thereof.

As with the CTOD 30 and the CTOD 90, the operator can select the desiredperformance of the CTOD 100 by selecting one of the plurality ofswitches 74*, and, when the operator's finger is placed against thetrigger 20 and depressed to pull the trigger 20, the contact switch 80*is closed, and the contact switch 80* transmits a signal to theprogrammable logic controller 72* in the drive mechanism 101. Inresponse to receiving the signal, the programmable logic controller 72*causes current to be intermittently and cyclically supplied to thesolenoid, according to the pre-programmed control instructionscorresponding to the selected one the of the plurality of switches 74*,causing the solenoid 102 to reciprocate, and causing the cable 75* to beintermittently and cyclically retracted. In response, the operator'sindex finger, applied in the index finger stall 45* is intermittentlyand cyclically retracted toward the extended position alongdouble-arrowed arcuate line A* in FIG. 3A. The operator, however,continues to hold his finger down in the curled position to depress thetrigger 20. When the solenoid 102 retracts the cable 75*, a greaterforce is applied to the operator's finger than he applies to it, so thatthe finger is pulled to the extended position. In the extended positionof the finger, the finger is pulled off of or away from the trigger 20,and the trigger 20 is returned to the ready position by the spring orother mechanism which returns the trigger 20 to the ready position. Whenthe solenoid 102 has retracted a full stroke, the application of currentto the solenoid 102 is removed, as instructed by the programmable logiccontroller 72*, the operator's own force on his finger is now able toovercome the solenoid 102, and his finger curls along line A* to depressthe trigger 20. When his finger depresses the trigger 20, it extends thesolenoid 102 a full stroke length so that the solenoid 102 is ready toretract. With the operator continuing to curl his finger, and thesolenoid 102 intermittently and cyclically retracting the cable 75* tointermittently and cyclically extend the finger, the operator's fingeris intermittently and cyclically curled and extended, and the trigger 20is intermittently and cyclically depressed to the depressed position andallowed to return to the ready position. In this way, the firearm 10intermittently and rapidly fires bullets, emulating fully-automaticfire.

A Fourth Embodiment

FIG. 3B illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 110. The CTOD 110 is adapted to be usedwith the firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 110 isvery similar to the CTOD 100 and includes many identical structuralfeatures elements with the CTOD 100. Those structural features andelements of the CTOD 110 which are identical to corresponding structuralfeatures and elements in the CTOD 100 are marked with identicalreference characters, but are designated with a double asterisk (“**”)symbol to distinguish them from those of the CTOD 100. In some cases,the CTOD 110 has identical structural features and elements as the CTOD100 but located in alternate locations. In such cases, the samereference character will be used, with the prime symbol, but thealternate location will be described. Where the CTOD 110 has identicalstructural features and elements as the CTOD 100 and those structuralfeatures and elements are located and used in an identical manner as inthe CTOD 100, they will merely be listed, as describing them would beunduly repetitive and burdensome for the reader. It should beunderstood, then, that the description for the particular structuralfeature or element with respect to the CTOD 100 is equally applicable tothe corresponding identical structural feature and element with respectto the CTOD 110, unless otherwise described. Finally, for simplicity ofthe illustrations, not all identical reference characters will be shown,if their corresponding identical reference characters are shown in afigure illustrating an alternate embodiment.

The CTOD 110 includes a glove body 31**, a dorsal side 32**, a palmarside 33**, a proximal end 34**, a distal end 35**, an opening 36**, anexterior surface 40**, an interior surface 41**, a strap 42**, a thumbstall 44**, an index finger stall 45**, and finger stalls 46**. The CTOD110 includes a base pad 50**, a spar 51** extending from a distal end63** at the base pad 50** to an axle 64**, and a pull 52** pivoted tothe axle 64** on the spar 51** for movement along the double-arrowedarcuate line A** in FIG. 3B. The pull 52** includes a proximal end 53**,a hole 54**, struts 55** and 56**, a stop 57**, a distal end 60**, acradle 61**, a hole 62**, and a contact switch 80**. The base pad 50**also carries an electronic solenoid 102**, which is coupled to the pull52** with a cable 75**. The solenoid 102** includes a piston or pistonhead that reciprocates through a stroke that is generally alignedparallel to the length of the spar 51*. However, the battery 103**, theprogrammable logic controller 72**, and the switches 74** are each offof the glove body 31**, preferably on a mount or platform 91** carriedon a belt 92** around the operator's waist. A long cable 111 extendsfrom the battery 103**, off the belt 92**, across the operator's torso,down the operator's arm, and onto the base pad 50**, where the cable 111couples with the solenoid 102** to provide current to the solenoid102**. With the battery 103** located off the glove body 31**, alarger-sized battery 103** is carried than in the CTOD 100, so that thebattery 103** lasts longer and provides more current, and thus needs tobe replaced less frequently than with the CTOD 100.

Operation of the CTOD 110 is similar to that of the CTOD 100. The pistonin the solenoid 102** intermittently and cyclically reciprocates betweena forward position and a retracted position in the solenoid 102**.Current is supplied to the solenoid 102** through the cable 111 from thebattery 103**. Actuation of the solenoid 102** retracts the cable 75**.When the index finger stall 45** is bent, such as would occur when afinger applied to the index finger stall 45** is curled around thetrigger 20, the cable 75** is extended and ready to be retracted so asto extend the index finger stall 45** and the index finger appliedthereto. When the cable 75** is retracted, the cable 75** is drawn back,and the proximal end 53** of the pull 52** is drawn toward the proximalend 34** of the glove body 31** to move the pull 52** into the secondposition thereof. This causes the index finger stall 45** to straighten.When the solenoid 102** retracts the cable 75** quickly, the operator'sindex finger is quickly returned toward the extended position thereof.

A Fifth Embodiment

FIG. 4A illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 120. The CTOD 120 is adapted to be usedwith the firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 120 issimilar to the CTOD 30 and includes many identical structural featureselements with the CTOD 30. Those structural features and elements of theCTOD 120 which are identical to corresponding structural features andelements in the CTOD 30 are marked with identical reference characters,but are designated with a tilde (“˜”) symbol to distinguish them fromthose of the CTOD 30. Where the CTOD 120 has identical structuralfeatures and elements as the CTOD 30, they will merely be listed, asdescribing them would be unduly repetitive and burdensome for thereader. It should be understood, then, that the description for theparticular structural feature or element with respect to the CTOD 30 isequally applicable to the corresponding identical structural feature andelement with respect to the CTOD 120, unless otherwise described.Finally, for simplicity of the illustrations, not all identicalreference characters will be shown, if their corresponding identicalreference characters are shown in a figure illustrating an alternateembodiment.

The CTOD 120 includes a glove body 31˜, a dorsal side 32˜, a palmar side33˜, a proximal end 34˜, a distal end 35˜, an opening 36˜, an exteriorsurface 40˜, an interior surface 41˜, a strap 42˜, a thumb stall 44˜, anindex finger stall 45˜, and finger stalls 46˜. The CTOD 120 includes abase pad 50˜, a spar 51˜ extending from a distal end 63˜ at the base pad50˜ to an axle 64˜, and a pull 52˜ pivoted to the axle 64˜ on the spar51˜ for movement along the double-arrowed arcuate line A˜ in FIG. 2C.The pull 52˜ includes a proximal end 53˜, a hole 54˜, struts 55˜ and56˜, a stop 57˜, a distal end 60˜, a cradle 61˜, a hole 62˜, and acontact switch 80˜.

The base pad 50˜ carries a drive mechanism 121 for controlling themovement of the pull 52˜ and the index finger stall 45˜. The drivemechanism 121 includes a lever arm 122 having a pivot end 123 secured tothe base pad 50˜ and an opposed free end 124. A cable 75˜ extends fromthe free end 124 to the hole 54˜ in the proximal end 53˜ of the pull52˜, so that movement of the lever arm 122 imparts movement to the cable75˜ and thus also to the pull 52˜. The drive mechanism 121 also includesan eccentric 125 mounted for rotational movement on the base pad 50˜.The eccentric 125 is disposed proximate to the lever arm 122 between thepivot and free ends 123 and 124. The eccentric 125 is mounted to a motor130, powered by a battery 131 on the base pad 50˜, and as the motorrotates the eccentric 125, which has an off-center axis of rotation, theeccentric 125 rotates as a plain bearing against the lever arm 122,causing the lever arm 122 to pivot cyclically, or oscillate, about thepivot end 123 in response to the rotational movement of the eccentric125. An onboard programmable logic controller 72˜ is mounted on the basepad 52˜ and powered by the battery 131. The programmable logiccontroller 72˜ controls the provision of current to the motor 130, andthus controls the rotation of the eccentric 125 and the oscillation ofthe lever arm 122. A plurality of switches 74˜ are also carried on thebase pad 52˜ and coupled to the programmable logic controller 72˜, sothat the user may depress or select one of the plurality of switches toinstruct the programmable logic controller to control the drivemechanism 121 in a particular, pre-programmed way.

The lever arm 122 oscillates between a forward position and a retractedposition. Actuation of the lever arm 122 in the retracted positionretracts the cable 75˜. When the index finger stall 45˜ is bent, such aswould occur when a finger applied to the index finger stall 45˜ iscurled around the trigger 20, the cable 75˜ is extended and ready to beretracted so as to extend the index finger stall 45˜ and the indexfinger applied thereto. When the cable 75˜ is retracted, the cable 75˜is drawn back, and the proximal end 53˜ of the pull 52˜ is drawn towardthe proximal end 34˜ of the glove body 31˜ to move the pull 52˜ into thesecond position thereof. This causes the index finger stall 45˜ tostraighten. When the lever arm 122 retracts the cable 75˜ quickly, theoperator's index finger is quickly returned toward the extended positionthereof.

As with the other embodiments of the CTOD 30, 90, 100, and 110, theoperator can select the desired performance of the CTOD 120 by selectingone of the plurality of switches 74˜, and, when the operator's finger isplaced against the trigger 20 and depressed to pull the trigger 20, thecontact switch 80˜ is closed, and the contact switch 80˜ transmits asignal to the programmable logic controller 72˜ in the drive mechanism121. In response to receiving the signal, the programmable logiccontroller 72˜ causes current to be supplied to the motor 130 to rotate,according to the pre-programmed control instructions corresponding tothe selected one the of the plurality of switches 74˜. In response, theeccentric 125 rotates against the lever arm 122, imparting oscillatorymovement to the lever arm 122. The cable 75˜, connected to the free end124 of the lever arm 125, is intermittently and cyclically retracted inresponse. This causes the pull 52˜ to intermittently and cyclically movealong the double-arrowed arcuate line A˜, and, in response, theoperator's index finger, applied in the index finger stall 45˜ isintermittently and cyclically retracted toward the extended positionalong line A˜ in FIG. 4A. The operator, however, continues to hold hisfinger down in the curled position to depress the trigger 20.

When the lever arm 122 retracts the cable 75˜, a greater force isapplied to the operator's finger than he applies to it, so that thefinger is pulled to the extended position. In the extended position ofthe finger, the finger is pulled off of or away from the trigger 20, andthe trigger 20 is returned to the ready position by the spring or othermechanism which returns the trigger 20 to the ready position. When thelever arm 122 has retracted a full stroke, the eccentric is in contactwith the lever arm 122 and is about to rotate to a low displacementposition in its cycle, as instructed by the programmable logiccontroller 72˜, and so the operator's own force on his finger is nowable to overcome the lever arm 122, and his finger curls along line A˜to depress the trigger 20. When his finger depresses the trigger 20, itmoves the lever arm 122 into the forward position thereof, where thelever arm 122 is ready to be pushed back into the retracted position bythe rotating eccentric 125. With the operator continuing to curl hisfinger, and the lever arm 122 intermittently and cyclically retractingthe cable 75˜ so as to intermittently and cyclically extend the finger,the operator's finger is intermittently and cyclically curled andextended, and the trigger 20 is intermittently and cyclically depressedto the depressed position and allowed to return to the ready position.In this way, the firearm 10 intermittently and rapidly fires bullets,emulating fully-automatic fire.

A Sixth Embodiment

FIG. 4B illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 140. The CTOD 140 is adapted to be usedwith the firearm 10 of FIG. 1 to enable the operator to quickly andcyclically depress the trigger 20 of the firearm 10. The CTOD 140 isvery similar to the CTOD 120 and includes many identical structuralfeatures elements with the CTOD 120. Those structural features andelements of the CTOD 140 which are identical to corresponding structuralfeatures and elements in the CTOD 120 are marked with identicalreference characters, but are designated with a double tilde (“˜˜”)symbol to distinguish them from those of the CTOD 120. In some cases,the CTOD 140 has identical structural features and elements as the CTOD120 but located in alternate locations. In such cases, the samereference character will be used, with the prime symbol, but thealternate location will be described. Where the CTOD 140 has identicalstructural features and elements as the CTOD 120 and those structuralfeatures and elements are located and used in an identical manner as inthe CTOD 120, they will merely be listed, as describing them would beunduly repetitive and burdensome for the reader. It should beunderstood, then, that the description for the particular structuralfeature or element with respect to the CTOD 120 is equally applicable tothe corresponding identical structural feature and element with respectto the CTOD 140, unless otherwise described. Finally, for simplicity ofthe illustrations, not all identical reference characters will be shown,if their corresponding identical reference characters are shown in afigure illustrating an alternate embodiment.

The CTOD 140 includes a glove body 31˜˜, a dorsal side 32˜˜, a palmarside 33˜˜, a proximal end 34˜˜, a distal end 35˜˜, an opening 36˜˜, anexterior surface 40˜˜, an interior surface 41˜˜, a strap 42˜˜, a thumbstall 44˜˜, an index finger stall 45˜˜, and finger stalls 46˜˜. The CTOD140 includes a base pad 50˜˜, a spar 51˜˜ extending from a distal end63˜˜ at the base pad 50˜˜ to an axle 64˜˜, and a pull 52˜˜ pivoted tothe axle 64˜˜ on the spar 51˜˜ for movement along the double-arrowedarcuate line A˜˜ in FIG. 4B. The pull 52˜˜ includes a proximal end 53˜˜,a hole 54˜˜, struts 55˜˜ and 56˜˜, a stop 57˜˜, a distal end 60˜˜, acradle 61˜˜, a hole 62˜˜, and a contact switch 80˜˜. The base pad 50˜˜also carries a cable coupling 141, to which the cable 75˜˜ is coupled,and which is inside of a coupling housing 142. A cable housing 143extends from the coupling housing 142 off the glove body 31˜˜ to a mountor platform 91˜˜ carried on a belt 92˜˜ around the operator's waist. Acable 144 is disposed within the cable housing 143 and is coupled to thecable coupling 141 in the coupling housing 142 at one end. At its otherend, the cable 144 is coupled to a free end 124˜˜ of a lever arm 122˜˜mounted for pivotal movement about a pivot end 123˜˜, so that the freeend 124˜˜ oscillates and imparts reciprocal movement to the cable 144.The platform 91 includes an eccentric 125˜˜ driving the lever arm, amotor 130˜˜ rotating the eccentric 125˜˜, and a battery 131˜˜ poweringthe eccentric 125˜˜, as well as a programmable logic controller 72˜˜ andswitches 74˜˜. The cable 144 is carried in the cable housing 143 withoutslack, so that movement of the free end 124 of the lever arm on theplatform 91 on the belt 92 immediately imparts movement to the cable75˜˜ and to the pull 52˜˜. With the battery 131˜˜ located off the glovebody 31˜˜, a larger-sized battery 131˜˜ is carried than in the CTOD 120,so that the battery 131˜˜ lasts longer and provides more current, andthus needs to be replaced less frequently than with the CTOD 120.

Operation of the CTOD 140 is similar to that of the CTOD 120. The motor130˜˜ rotates, according to the pre-programmed control instructionscorresponding to the selected one the of the plurality of switches 74˜˜.In response, the eccentric 125˜˜ rotates against the lever arm 122˜˜,imparting oscillatory movement to the lever arm 122˜˜. The cable 144,connected to the free end 124˜˜ of the lever arm 125˜˜, isintermittently and cyclically retracted in response. This causes thecable 75˜˜, on the glove boy 31˜˜ and to which the cable 144 isattached, to also intermittently and cyclically retract. In turn, thiscauses the pull 52˜˜ to intermittently and cyclically move along thedouble-arrowed arcuate line A˜˜, and, in response, the operator's indexfinger, applied in the index finger stall 45˜˜ is intermittently andcyclically retracted toward the extended position along line A˜˜ in FIG.4B. The operator, however, continues to hold his finger down in thecurled position to depress the trigger 20. When the index finger stall45˜˜ is bent, such as would occur when a finger applied to the indexfinger stall 45˜˜ is curled around the trigger 20, the cable 75˜˜ isextended and ready to be retracted so as to extend the index fingerstall 45˜˜ and the index finger applied thereto. When the cable 75˜˜ isretracted, the cable 75˜˜ is drawn back, and the proximal end 53˜˜ ofthe pull 52˜˜ is drawn toward the proximal end 34˜˜ of the glove body31˜˜ to move the pull 52˜˜ into the second position thereof. This causesthe index finger stall 45˜˜ to straighten. When the lever arm 122˜˜oscillates to the rearward position thereof, it retracts the cable 75˜˜quickly, and the operator's index finger is quickly returned toward theextended position thereof.

A Seventh Embodiment

FIG. 5 illustrates an embodiment of the present invention, constructedand arranged according to the principle of the invention, referred to asa cyclical trigger operation device (hereinafter, “CTOD”) and markedwith the reference character 150.

The CTOD 150 is rail-mounted to a barrel 14 of the firearm 10, asfirearm accessories commonly are, and is adapted to enable the operatorto quickly and cyclically depress the trigger 20 of the firearm 10. TheCTOD 150 includes a pull 151 and a housing 152 containing a drivemechanism 153 coupled to the pull 151 to impart intermittent andcyclical movement to the pull 151. The pull 151 is a solid body in theform of a loop or ring sized and shaped to receive a finger. The pull151 is rigid and is sized to fit in the finger gap 24 in front of thetrigger 20 on the firearm 10. A cable 154 is secured to the pull 151 andextends forwardly to the drive mechanism 153 in the housing 152. FIG. 5shows the interior of the housing 152, as it would appear with a coverremoved, for clarity of the illustration and description.

The drive mechanism 153 of the CTOD 150 is identical to the drivemechanism 153 of the CTOD 30. It includes a pneumatic cylinder 160 witha stroke that is generally aligned along the length of the barrel 14.The drive mechanism 153 has a gas supply 161 to supply a gas to thepneumatic cylinder 160. In FIG. 5, the gas supply 161 is a cylindricalhousing. The gas supply 161 is preferably replaceable gas cartridges,such as CO2 cartridges. The CO2 cartridges can be coupled to thepneumatic cylinder 160. A programmable logic controller 162 is carriedin the housing 152 and is powered by a small battery 163. Theprogrammable logic controller 162 controls the application and removalof gas to and from the pneumatic cylinder 160. A plurality of switches164 are also carried in the housing 152 and are coupled to theprogrammable logic controller 162, so that the user may depress orselect one of the plurality of switches to instruct the programmablelogic controller to control the drive mechanism 153 in a particular,pre-programmed way, as is discussed later. Though the drive mechanism153 shown in FIG. 5 is identical to the drive mechanism 65 used with theCTOD 30, one having ordinary skill in the art will readily appreciatethat the drive mechanism 153 may be replaced with the drive mechanisms101 or 121 for the CTODs 100 and 120, respectively. When the drivemechanism 121 is sued, it is preferable that the cable 75˜ is routedthrough one or several pulleys to increase the retracting force of thelever arm 122.

The cable 154 extends from the pneumatic cylinder 160 to the pull 151,thereby operatively coupling the drive mechanism 153 to the pull 151 toimpart movement to the pull 151 in response to actuation of the drivemechanism 153. The pneumatic cylinder 160 is aligned with the movementof the trigger 20, and the cable 154 is coupled to a piston in thepneumatic cylinder 160. The piston in the pneumatic cylinder 160intermittently and cyclically reciprocates between a forward positionand a retracted position in the pneumatic cylinder 160. Actuation of thepneumatic cylinder 160 retracts the cable 154.

In operation, an operator selects the desired performance of the CTOD150 by selecting one of the plurality of switches 164, and thenenergizes the CTOD 150. The switches 164 each correspond to variousperformance functions of the CTOD 150. Some of the switches allow theoperator to select a cycling speed. For instance, the operator mayselect a switch setting the cycling speed at three hundred rpm, inresponse to which the pneumatic cylinder will reciprocate approximatelythree hundred times in one minute to cycle movement of the pull 151three hundred times in a minute, emanating a fast firing firearm. Inanother example, the operator may select a switch setting the cyclingspeed at nine hundred rpm, in response to which the pneumatic cylinderwill reciprocate approximately nine hundred times in one minute to cyclemovement of the pull 151 nine hundred times in a minute, emulating avery fast firing firearm. Some of the switches allow the operator toselect a cycling duration. For example, the operator may select a switchsetting the cycling duration to three pulses, in which case thepneumatic cylinder will reciprocate three times, so as to emulate athree-round burst of fire. In another example, the operator may select aswitch setting the cycling duration to five pulses, in which case thepneumatic cylinder will reciprocate five times, so as to emulate afive-round burst of fire. In yet another example, the operator mayselect a switch setting the cycling duration to two seconds, in whichcase the pneumatic cylinder will reciprocate for two seconds, so as firerepeatedly for two seconds and then pause or stop.

After the performance of the CTOD 150 is set, the operator grips thefirearm 10 at the pistol grip 21, placing his index finger proximate tothe trigger 20. He then places his index finger through the pull 151until the pull 151 fully and securely encircles his index finger. Insome cases, a thimble may be worn which has a hook to improve thesecurement of the pull 151. The operator shoulders or readies thefirearm 10 and takes aim at a target. Once a target is acquired, theoperator fires the weapon by placing his finger against the trigger 20and depressing or pulling the trigger 20 back toward the grip 21.

Upon the operator initially energizing the CTOD 150, the programmablelogic controller 162 receives an activation signal and causes gas to beintermittently and cyclically supplied to and drawn from the pneumaticcylinder 160, such as through an on-board valve, according to thepre-programmed control instructions corresponding to the selected onethe of the plurality of switches 164, causing the pneumatic cylinder 160to reciprocate, and causing the cable 154 to be intermittently andcyclically retracted. In response, the operator's index finger, appliedin pull 151, is intermittently and cyclically retracted toward theextended position along double-arrowed arcuate line B in FIG. 5. Theoperator, however, continues to hold his finger down in the curledposition to depress the trigger 20. When the pneumatic cylinder 160retracts the cable 154, a greater force is applied to the operator'sfinger than he applies to it, so that the finger is pulled to theextended position. In the extended position of the finger, the finger ispulled off of or away from the trigger 20, and the trigger 20 isreturned to the ready position by the spring or other mechanism whichreturns the trigger 20 to the ready position. When the pneumaticcylinder 160 has retracted a full stroke, the supply of gas to thepneumatic cylinder 160 is removed, as instructed by the programmablelogic controller 162, the operator's own force on his finger is now ableto overcome the pneumatic cylinder 160, and his finger curls along lineB to depress the trigger 20. When his finger depresses the trigger 20,it extends the pneumatic cylinder 160 a full stroke length so that thepneumatic cylinder 160 is ready to retract. With the operator continuingto curl his finger, and the pneumatic cylinder 160 intermittently andcyclically retracting the cable 154 to intermittently and cyclicallyextend the finger, the operator's finger is intermittently andcyclically curled and extended, and the trigger 20 is intermittently andcyclically depressed to the depressed position and allowed to return tothe ready position. In this way, the firearm 10 intermittently andrapidly fires bullets, emulating fully-automatic fire.

The present invention is described above with reference to a preferredembodiment. However, those skilled in the art will recognize thatchanges and modifications may be made in the described embodimentwithout departing from the nature and scope of the present invention. Tothe extent that such modifications and variations do not depart from thespirit of the invention, they are intended to be included within thescope thereof.

Having fully and clearly described the invention so as to enable onehaving skill in the art to understand and practice the same, theinvention claimed is:
 1. A device for cyclically operating a trigger ofa firearm, the device comprising: biasing means for biasing a fingerapplied to a trigger away from the trigger; and a contact switch coupledto the biasing means and configured to be disposed between the fingerand the trigger; wherein in response to the contact switch detectingcontact between the finger and the trigger, the biasing means actuatesto cyclically bias the finger away from the trigger.
 2. The device ofclaim 1, wherein the contact is a pressure switch.
 3. The device ofclaim 1, wherein the biasing means includes: a pull; and a drivemechanism operatively coupled to the pull to move the pull from a firstcondition, proximate to the trigger, to a second position, away from thetrigger.
 4. The device of claim 3, wherein the pull includes one of acradle configured to receive the finger and a loop sized to receive thefinger.
 5. The device of claim 3, wherein: the drive mechanism includesa pneumatic cylinder and a gas supply coupled in gaseous communicationto the pneumatic cylinder; and the pneumatic cylinder is coupled to thepull to move the pull into the second position thereof.
 6. The device ofclaim 3, wherein: the drive mechanism includes a solenoid and a batterycoupled to the solenoid to provide power to the solenoid; and thesolenoid is coupled to the pull to move the pull into the secondposition thereof.
 7. The device of claim 3, wherein: the drive mechanismincludes an eccentric mounted for rotational movement; and the eccentricis operatively coupled to the pull to move the pull into the secondposition thereof.
 8. The device of claim 7, wherein: the drive mechanismfurther includes a lever arm having a pivot end and a free end; the freeend of the lever arm is coupled to the pull; and the eccentric is incontact with the lever between the pivot and free ends to impart pivotalmovement to the lever arm in response to rotational movement of theeccentric, so as to move the pull into the second position thereof. 9.The device of claim 8, wherein the cradle includes a central hole formedtherethrough providing a contact space for the finger fit through thefinger stall to contact a trigger.
 10. A method for aiding in operatinga trigger of a firearm with a finger, the method comprising the stepsof: providing a firearm with a trigger; providing a device including apull and a drive mechanism operatively coupled to move the pull in afirst direction; applying the pull to the finger; depressing the fingeragainst the trigger; and activating the drive mechanism, the drivemechanism moving the pull in the first direction, the pull retractingthe finger from the trigger in response to moving in the firstdirection.
 11. The method of claim 10, further comprising: providing acontact switch; and the step of activating the drive mechanism occurs inresponse to the contact switch detecting the depressing of the fingeragainst the trigger.
 12. The method of claim 10, wherein: the step ofdepressing the finger against the trigger further includes continuouslydepressing the finger against the trigger; and the step of activatingthe drive mechanism further includes cyclically activating the drivemechanism.
 13. The method of claim 10, wherein the step of activatingthe drive mechanism further includes activating the drive mechanism atone of a plurality of frequencies.
 14. The method of claim 10, whereinthe step of activating the drive mechanism further includes activatingthe drive mechanism for one of a plurality of durations.